The existence of hidden extra dimensions in our world could be manifested by the weakening of gravitational waves, but accurate calculations did not reveal it.
Back in the early twentieth century, General Relativity predicted the existence of gravitational waves - deformations of space-time emitted by moving masses. However, it was possible to register them only 2.5 years ago: powerful gravitational waves arose during the catastrophic merger of black holes. Last year, the LIGO and VIRGO interferometer detectors caught a wave from the merger of a pair of massive neutron stars, which was also observed with conventional telescopes.
The analysis of the data collected then continues to this day. In another work based on LIGO observations, the team of University of Chicago professor Daniel Holz (Daniel Holz) considered the problem of the existence of dark energy. According to modern estimates, this mysterious entity accounts for about 3/4 of the mass-energy of the Universe, so on a large scale it not only counteracts gravity, but also defeats it. However, we still cannot say what it really is.
In an article published in the Journal of Cosmology and Astroparticle Physics, Holtz and colleagues examined one hypothesis for dark energy that sees it as a manifestation of the extra dimensions of our spacetime. Unlike the three "main" dimensions of space, they are curtailed and do not appear on the scales available to us. However, it is in them that part of the gravitational energy can "flow away", weakening its action.
Observations of the merger of neutron stars, which were carried out on August 17, 2017, on both gravitational and electromagnetic waves (from radio and visible radiation up to X-rays and gamma rays), allowed scientists to test this hypothesis. They helped assess the true strength of this distant event and the amount of energy that was scattered with gravitational waves. If part of it "leaks" into extra dimensions, the waves should be weaker than the calculations predict. However, Holtz and his colleagues did not find this - at least not at the level of accuracy available so far.
However, this has not yet solved the problem of extra dimensions. "There are many theories that we could not reliably test until recently," says one of the authors of the work Maya Fishbach (Maya Fishbach). "Now we are waiting for what new gravitational-wave surprises the Universe will throw at us."
Sergey Vasiliev